I’ve just recently started seeing an error message in the top right corner of my Monitor on boot up.
failed to load hat overlay
dterror not a valid FDT -err -9
It appears to be caused by my Breakout Garden i2c hat? If I remove it the message goes away.
Says I have the latest version.
sudo apt update
sudo apt upgrade
sudo apt full-upgrade
sudo apt install rpi-eeprom
All report fully up to date, 0 installed etc.
Pi 400 running 32 bit Bullseye, official release. Custom modified pHat Stack plugged into Pi’s GPIO, no ribbon cable. All the inserted breakouts are running fine with no errors in Python.
EDIT: It’s not from my modified pHat Stack, same error with a Pi 400 Flat Hat Hacker and the i2c Hat.
If you add the following entry to your config.txt file it will be suppressed and go away.